On the genesis of inflated (and deflated) judgments of responsibility

Prior research has found that people tend to overestimate their relative contribution to joint tasks [e.g., Ross, M., & Sicoly, F. (1979). Egocentric biases in availability and attribution. Journal of Personality and Social Psychology, 37, 322-336]. The present research investigates one source of this bias, and in doing so, identifies an important moderator of the effect. Three studies demonstrate that when people estimate their relative contribution to collective endeavors they focus on their own contribution and give less consideration to the contribution of their collaborators. This can cause overestimation for tasks in which total contributions are plentiful, but underestimation for tasks in which total contributions are few--despite the fact that both tasks reflect positively on the person who performs them. These results extend Ross and Sicoly's (1979) original analysis of bias in responsibility judgments, but also suggest that the tendency to overestimate one's relative contribution to collaborations is not as ubiquitous as once thought.